The invention relates to a fuel injection system for internal combustion engines having a distributing conduit, comprising two shaped parts joined by means of flanges in a longitudinal plane, and to which are connected several injection valves by means of pairs of coupling bushings and coupling nipples.
A conventional fuel injection system of this general type of structure (DOS No. 2,833,659) comprises a distributing conduit with an inner part of an elastomer with molded-on coupling bushings, this inner part being encompassed by the two shaped components. The flange plane of the shaped parts contains the axes of symmetry of the distributing conduit and of the coupling bushings so that the shaped parts represent essentially half shells of mirror-image symmetry. This construction of the distributing conduit results in a complicated and expensive fuel injection installation, since it is not only necessary to manufacture the inner part of the distributing conduit separately, but furthermore the configuration of the coupling nipples of the injection valves deviates from the customary, mass-produced shape with O-ring seal. Besides, the distributing conduit disadvantageously has a relatively heavy weight.
In another known fuel injection system (German Utility Model No. 7,918,697), a square pipe sealed at the ends is utilized as the distributing conduit, this pipe having coupling bushings soldered into bores. The injection nozzles, sealingly inserted in the coupling bushings by means of radially acting O-rings on their coupling nipples, are axially fixed in position by means of spring clips. Here again, the manufacture of the distributing conduit is complicated and expensive, since the coupling bushings must be produced separately and must be soldered into holes in the distributing conduit.